At the Transformational Climate Science conference in my home town, Exeter, UK, earlier this month, senior IPCC author Ottmar Edenhofer discussed the ‘battle’ with governments on his part of the report. Another scientist who worked on the report highlighted confidentially to me how unusual the omission was.

To me, it’s more surprising that this hasn’t happened more often, especially when you look more closely at the latest report’s findings. There’s concrete certainty that warming is happening, and it’s extremely likely that humans are the dominant cause, it says. Governments have even – in some cases, begrudgingly – already signed up to temperature and CO2 emission targets reflecting this fact.

The inadequacy of those words is becoming ever more starkly obvious. Ottmar stressed that the emissions levels agreed at the United Nations’ Climate Change Conference in Cancún, Mexico, in November 2010, would likely need later emissions cuts the likes of which we’ve never seen before to avoid dangerous climate change. The latest IPCC report shines a floodlight on that inertia, which understandably cranks up the tension between researchers and politicians.

Ottmar was one of two co-chairs who led the ‘working group three’ (WGIII) section of the IPCC report that looks at how to cut greenhouse gas emissions. He stressed that the need to make these cuts comes from a fundamental difference between the risks that come from climate change and the risks of mitigation. We can heal economic damage arising from cutting emissions – reversing sea level rise isn’t so easy.

Although CO2 can stay in the atmosphere, trapping heat, for thousands of years scientists think they have turned it into rock in just a few months. Juerg Matter from the University of Southampton, UK, and his colleagues in the CarbFix project have injected 170 tons of pure CO2 into the reactive basalt underneath Iceland. Their findings suggest around 85% of it reacted with the rock over the short distance between injection and monitoring boreholes in less than one year.

“We think that was because all that CO2 precipitated out as carbonate minerals in the reservoir,” Juerg, who’s also an adjunct scientist at Lamont-Doherty Earth Observatory in New York, told me. “To really prove it this summer we will drill a borehole into the injection reservoir to retrieve rock core samples.” But the CarbFix team has also emphasised this week that it will take higher carbon prices for this and other carbon capture and storage technology to fulfil their potential.

In the air, CO2 eventually reacts with basalt naturally, but that process is far too slow to balance out what humans are emitting. Since 2007 the CarbFix team has been working to see if they can speed that process up by forcing CO2 underground. Not only would this quickly turn the gas into minerals and prevent leak worries, it would also greatly expand the number of places it could be stored. “The storage potential is just huge, there’s billions of tons of reservoir, because basically all the ocean floor is basalt,” Juerg highlighted. Read the rest of this entry »

University of Victoria’s Andrew MacDougall in Canada’s Kluane National Park Credit: Nicolas Roux

If CO2 levels in the air pass the ‘safe’ limit, we’d have to take out up to four-fifths more than we originally emitted to get back under it. That’s the result from seemingly the first study to look at climate change’s reversibility with plausible scenarios, done by Andrew MacDougall from the University of Victoria (UVic), Canada. “With monumental effort and political will climate change is reversible within the millennium,” Andrew told me. “However, more carbon will need to be extracted from the atmosphere than was originally emitted to it. Meanwhile, changes in sea-level are effectively irreversible on the millennial time-scale.”

Andrew started looking at whether climate change could be undone in autumn 2012, after publishing a study showing that melting permafrost will speed up global warming. “The results were pretty grim,” Andrew said. “Combined with the failure of the political classes to implement controls on carbon emissions I began to wonder if there was a way to undo what humanity will do to the climate if we greatly exceeded the 450 parts per million (ppm) target.” That target comes because scientists say temperatures 2°C higher than the ‘pre-industrial’ average from 1850-1899 could become dangerous, and governments have agreed to keep warming below this level. Scientists also calculate that 450 CO2 molecules are allowable in every million air molecules to give us better than a 3/5 chance of temperature rises below 2°C.

On the wall of Wally Broecker’s building at the Lamont-Doherty Earth Observatory hangs a 16-foot long terry-cloth snake, blue with pink spots, that he calls the ‘climate beast’. Left in his office as a surprise by his workmates, its name refers to one of Wally’s most powerful quotes about the climate: “If you’re living with an angry beast, you shouldn’t poke it with a sharp stick.”

Today, the sharp stick is the CO2 we’re emitting by burning fossil fuels, which Wally was warning about by 1975. By that time he had also helped confirm that throughout history, changes in Earth’s orbit have given the climate beast regular kicks, triggering rapid exits from ice ages. He became obsessed with the idea that climate had changed abruptly in the past, and the idea we could provoke the ‘angry beast’ into doing it again.

Among the many samples that Wally was carbon dating, from the late 1950s onwards he was getting treasure from the oceans. Pouring sulphuric acid into seawater, he could convert dissolved carbonate back into CO2 gas that he could then carbon date. And though nuclear weapon tests had previously messed with Wally’s results, they actually turned out to help improved our knowledge of the oceans. The H-bomb tests produced more of the radioactive carbon-14 his technique counts, and as that spike moved through the oceans, Wally could track how fast they absorbed that CO2.

Sometimes, climate change seems unstoppable – so much so, it’s tempting to ask: ‘Why bother doing anything about it then?’ Steven Davis of the Carnegie Institution of Washington and his colleagues have provided one answer. They have found that while the power generation facilities and transportation we currently use guarantee some CO2 emissions, those emissions will not themselves reach levels that could cause dangerous climate change.

“The result is hopeful in that what we’ve already built won’t put us over the 2ºC benchmark,” Davis said. A 2°C temperature rise from pre-industrial averages is a stated aim of the Copenhagen Accord, agreed by the world’s countries in December last year. However, Davis warns that taking the right steps to stop emitters yet to be built taking global temperature rises through this limit is a difficult, in fact almost impossible, challenge. “The necessary transition in our energy system is incredibly daunting,” he explains. “The immensity of the challenge is not commonly understood, the political will is lacking, and there are few alternative energy technologies that can attain the required scale.” Read the rest of this entry »

Beijing Normal University’s John Moore, who is also affiliated with the University of Lapland and the University of Oulu in Finland. Credit: Beijing Normal University

Climate change is leaving the world’s northernmost inhabitants literally lost for words, according to Beijing Normal University‘s John Moore. “Arctic indigenous people have no local names for bird species migrating into their areas, showing that they have not been seen over the history of their oral tradition,” he explains. Moore also has his own personal connection to the impact of global warming, with ice shelves in Antarctica where he worked in the 1980s having ceased to exist since. Moore expects that further breakup and retreat of ice will follow as temperatures rise. “Dramatic changes are very clearly seen in glaciers in many mountain regions, Greenland’s melting and glacier flow, and the on-going acceleration of glaciers in parts of West Antarctica,” he says.

While these likely impacts are clear, other future happenings are not. “We have been doing a CO2 experiment for centuries and we are still not sure of all the detailed impacts,” Moore says. We know less still about a group of suggested methods for tackling climate change without reducing greenhouse gas emissions, together known as geo-engineering, making using them a potentially high-risk strategy, Moore notes. “Modifying the climate is bound to be risky since every living thing depends on it,” he says. “Human civilization is about as old as the stable climate period of the Holocene,” Moore says. “We know that over the previous 100,000 years climate was very unstable compared with this period. It seems civilization’s origins relied on a stable climate – cities dependent on agriculture would have been unsustainable in a variable climate.” However, geo-engineering could help keep the climate stable while we reduce our greenhouse gas emissions, he adds. “There may be real benefits in helping to get us over the fossil fuel dependency and on to a more sustainable track.” Read the rest of this entry »

If CO2 emissions can’t be cut, simulating volcanoes could help the 150 million people across the world threatened by rising sea levels, scientists said this week. But the UK, Denmark and China-based researchers who reach these conclusions also warn such ‘geo-engineering’ measures could be dangerous in other ways. “Substituting geo-engineering for greenhouse gas emission control would be to burden future generations with enormous risk,” said Svetlana Jevrejeva of the UK’s National Oceanography Centre.

150 million people worldwide are thought to live within 1 metre of high tide, Jevrejeva’s team notes. In 2007, the Intergovernmental Panel on Climate Change (IPCC) estimated that by 2100 the sea level would rise by 0.18–0.59 metres. However, since then several researchers have suggested a rise of 1-1.5 metres would be more likely. Read the rest of this entry »